Disk playback devices are already proposed in which a plurality of optically readable disks are arranged one above another and which are adapted to selectively play back one of the disks (see U.S. Pat. No. 5,123,001).
With reference to FIGS. 40 to 45 showing such a device, the main body 1 of the device is provided in its inside rear portion with a stacker 74 for accommodating a plurality of disks D as arranged one above another in layers. The stacker 74 has subtrays 58 for placing the respective disks D thereon. The stacker 74 is in mesh with rotatable worm shafts 59 extending upright from the bottom wall of the device body 1 and is thereby made movable upward and downward.
The device body 1 has a front panel 10, inside of which is provided an optical head base 27 for playing back the disk. Disposed above the head base 27 is a main tray 4 reciprocatingly movable from outside the body 1 to inside thereof and vice versa.
A clamp 57 for holding the disk is disposed above the main tray 4 and is movable upward and downward relative to the head base 27. The main tray 4 carrying the disk thereon is drawn into the device body 1 and opposed to the base 27. In this state, the clamp 57 descends to hold the disk D to the head base 27, whereby the disk is made ready for playback.
When the user is to place a new disk D on the main tray 4 for playback, the main tray 4 is withdrawn, the disk D is placed thereon, and the main tray 4 is stowed in the device body 1.
When the user is to play back a desired disk in the stacker 74, the user manipulates the front panel 10 first to give an input specifying the disk at the desired level within the stacker 74. This causes a drive mechanism to rotate the worm shafts 59 to raise the stacker 74 as seen in FIG. 42. The stacker 74 is halted at a position where the subtray 58 carrying the disk to be played back is located at the same plane as the main tray 4.
In this state, a transport mechanism (not shown) transfers the disk from the subtray 58 to the main tray 4, which moves horizontally to above the head base 27, rendering the disk ready for playback as stated above.
With the conventional disk playback device, the main tray 4 with the disk placed thereon is positioned above the head base 27 during disk playback, so that the main tray 4 alone is not movable during the playback of the disk. During playback, therefore, another disk can not be stowed in the device body 1 or withdrawn from the body 1 to the inconvenience of the user.